1. Field of the Invention
The present invention relates to a device for driving a screw, pin, rivet or the like into a threaded or drilled hole and more particularly relates to a manually operated device well adapted for use in fine hand works such as for driving a screw into a threaded hole or inserting a pin or rivet into a drilled hole.
2. Description of the Prior Art
In manufacturing, assembling or disassembling a variety of small-sized precision instruments and machines such as watch, clock or the like a large number of pincette or similar tool for locating and driving a screw, pin, rivet or the like into a threaded or drilled hole. Since the conventional fine hand works are entirely dependent on an operator's skill, they are performed at lower working efficiency with a great deal of fatigue of the operator.
Hitherto various devices of the kind for driving a screw, pin, rivet or the like into a threaded or drilled hole have been already proposed. However it is pointed out as drawbacks with the conventional devices that they are very complicated in structure, are expensive to be manufactured and have few reliability of operation.
In view of the above mentioned drawbacks of the conventional devices to be eliminated, the inventor made an invention which consists in an improved device of the kind which is intended to be considerably simple in structure and have an excellent reliability of firmly holding and driving a screw, pin, rivet or the like in association with locking operation. A patent was granted to the prior invention under U.S. Pat. No. 4,165,772. The device in accordance with the prior invention essentially comprises a rotary cylinder to which a grip end cylinder is rotatably attached, a center rod with its end secured to the rotary cylinder and having thereon a stopper, a thrust sleeve disposed on the fore side of the stopper along the center rod and having an annular notch formed at the fore and part thereof, a cylindrical press block displaceably mounted on the center rod with a spring extending from the stopper, a stationary cylinder containing the thrust sleeve and press block therein, said stationary cylinder being telescopically fitted into the rotary cylinder so that a relative sliding movement as well as a relative rotational movement are ensured between the both stationary and rotary cylinders, a swing lever having a pin depending therefrom, a top cylinder connected to the stationary cylinder and having an aperture through which the pin passes, a support block disposed within the top cylinder and so shaped as to swing-movably carry a pair of nozzle halves, and a nozzle consisting of the aforesaid nozzle halves and having a hook formed on one of the nozzle halves, said hook being adapted to be engaged to the annular notch in the thrust sleeve.
In fact the device of the prior invention succeeded in eliminating the drawbacks inherent to the conventional one, but it has been considered as another drawback to be eliminated that operation of the swing lever for controlling opening and closing of the nozzle is associated with locking movement of the thrust sleeve in a complicated manner.